The Weedinator uses a novel stepper motor driven system for it's 'suspension':

I've deliberately avoided the normal spring type suspension as the machine must not wobble about when the cultivating / weeding mechanism is working and the overall machine needs to be effectively 'rigid' in relation to the ground, although there will be some 'give' in the tyres.

The technical name for the motor is 'Non Captive Stepper Motor' and the one I'm using is a Nema 34 with a rated linear holding torque of 3500 N, so it was on planet earth and operating in parallel with the earth's core, it would hold still a massive 350 kg!

In the test I set the motor to 16 steps and maximum torque using an Arduino Mega and put about 500 N force on the motor BEFORE turning it on. As can be seen in the video below, the motor accelerated up to speed and moved up the spindle reasonably quickly: